<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <script>
        //变量
        let name = 'cbw'
        let age = 21

        name = 'cbw1'
        age = 20
        //常量
        const PI =3.1415
        const num = []
        const user = {
            name:"lisi",
            age: 18
        }
        const arr = [1,2,3]
        arr.push(4)
        console.log(arr)
        arr.shift()
        console.log(arr);

        const obj = {
            name: 'vue',
            age: 10
        }
        //添加属性
        obj.brith = 2015
        console.log(obj)
        //修改属性
        obj.age = 10
        console.log(obj)


</script>
</body>
</html>